fischerproj - Fischer projection that indicates the...

Drawing a Fischer projection Start with a three-dimensional picture of a tetrahedral C atom – the chiral C is at the center. We are starting out with a molecule in the S- configuration: COOH H 3 C OH H Whenever the C atoms in the main chain are all lying in the same plane as they are in the example above, rotate the molecule so that the CH 3 (that is the C atom with the bigger IUPAC number is pointing back (indicated by the broken line ----)). As done below: COOH HO H CH 3 Now draw the Fischer projection by putting the COOH on the top of the vertical line and the CH 3 at the bottom of the vertical line, the horizontal line will have the OH on the left and the H on the right end the chiral C is where the vertical and horizontal lines meet. As shown below: H HO COOH CH 3 We started with the molecule drawn in the S- configuration and so we have to end with a

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Unformatted text preview: Fischer projection that indicates the molecule is in the S- configuration. You will always be able to figure out if you got it right. ..because you know how to tell if the molecule is in an S- or R- configuration. Here we are going to look at the same molecule but this time its in the R- configuration and generate the Fischer projection for it: OH H CH 3 COOH for this molecule we need to put the COOH group on top (where the OH group is) as shown below: COOH HO CH 3 H Now we want the -CH 3 group to be pointing back (where the H is), so rotate the molecule again as shown below: COOH H OH CH 3 Now we can draw the Fischer projection with COOH on top and CH 3 on the bottom of the vertical line and the H on the left end and OH on the right end of the horizontal line. As shown below: OH H COOH CH 3...
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